An attachment device for attaching a fuel injector to an intake manifold, in which the fuel injector is axially fixed to the fuel distribution line and to a plug nipple via an attachment element designed as a U-shaped securing clamp having two legs which are flexible in the radial direction, is described, e.g., in published German patent document DE 29 26 490. When mounted, the securing clamp extends through corresponding notches in the plug nipple and can be clicked into place in a recess designed as an annular groove in a connector piece of the fuel injector. The axial play between the notches and the securing clamp and between the annular groove and the securing clamp is to be kept to a minimum, so that the fuel injector may be fixed precisely in place without strain on the seal.
The disadvantage of the attachment device disclosed in published German patent document DE 29 26 490 is the fact that the various holding components exert strain upon the fuel injector. The resulting flux of force in the fuel injector results in deformations and thereby in changes in the lift and even seizure of the valve needle, and also results in pressure load or bending load on the housing components, which as a general rule have thin walls and are welded to one another at various points. Moreover, every attachment means, e.g., a contact collar, increases the radial dimension of the fuel injector, which in turn means more space is required for installation.